the code showing error "Error using network/sim (line 271) Input data sizes do not match net.inputs{1}.size. Error in ann (line 40) y1 = sim(net,riii);".How to correct?

clear all;
close all;
files={'r1i.mat','r2i.mat','r3i.mat','r4i.mat'};
% s=load ('c1.mat');
% c(:,1)=mfcc';
% files = {'file1.mat', 'file2.mat', 'file3.mat', 'file4.mat'};
S = load(files{1});
for m = 2:numel(files)
    S(m,1) = load(files{m});
end
% C=[S(1,1) S(2,1) S(3,1) S(4,1) S(5,1) S(6,1) S(7,1) S(8,1) S(9,1) S(10,1) S(11,1) S(12,1) S(13,1) S(14,1) S(15,1) S(16,1) S(17,1) S(18,1) S(19,1) S(20,1) S(21,1) S(22,1) S(23,1) S(24,1) S(25,1) S(26,1) S(27,1) S(28,1) S(29,1) S(30,1) S(31,1) S(32,1) S(33,1) S(34,1) S(35,1) S(36,1) S(37,1) S(38,1) S(39,1) S(40,1) S(41,1) S(42,1) S(43,1) S(44,1) S(45,1) S(46,1) S(47,1) S(48,1) S(49,1) S(50,1)  ];

  A= struct2cell(S)';
    B= cell2mat(A);
 D=B';
t=zeros(2,2);

t(1,1:2)=1;
t(2,1:2)=0;
t(1,3:4)=0;
t(2,3:4)=1;

save D D;
save t t;
% TESTING
% load B.mat;
load t.mat;
ri=load('r1i.mat');
rii=struct2cell(ri);
riii=cell2mat(rii);
% ciiii=ciii';
save riii riii;
load riii.mat;
net = feedforwardnet(10);
net = train(net,D,t);
view(net)
y = net(D);
perf = perform(net,y,t);
 y1 = sim(net,riii');
 if (y1(1,1)>y1(2,1))
     o=1;
 elseif (y1(2,1)>y1(1,1))
     o=2;
 
 end

if o==1
    disp('Elephant is present');
    

elseif o==2
    disp('Elephant is not present ');


end